Workers remove a poster-banner for "The Interview" from a billboard in Hollywood, California, December 18, 2014 a day after Sony announced it was cancelling the movie's Christmas release due to a terrorist threat (AFP)

Russia has slammed the United States over a raunchy comedy featuring a fictional plot to kill North Korean dictator Kim Jong-Un, saying Pyongyang’s anger was understandable.

On Christmas Day, “The Interview” — which has become an unlikely symbol of free speech in the West — opened in crowded US movie theatres.

An expletive-laden tale full of sexual innuendo and scatological humour, the film’s future had been in doubt after entertainment giant Sony said it was cancelling the release following an embarrassing cyber-attack on its corporate network and threats against moviegoers.

The US has blamed the hacker attack on North Korea, and President Barack Obama has threatened reprisals.

Russia, which backs the Stalinist regime, said it was concerned by the latest escalation of tensions between the North and Washington and slammed the irreverent comedy.

“The very idea of the film is so aggressive and scandalous that the reaction of the North Korean side… is completely understandable,” foreign ministry spokesman Alexander Lukashevich said on Thursday.

Lukashevich said the United States had not provided any evidence linking North Korea to the hack attack, noting that Pyongyang offered Washington to conduct a joint investigation into the incident.

“In essence, such a step is evidence of the North Korean side’s sincere intention to fully sort out this issue,” Lukashevich said.

“We believe that the threats of revenge and calls on other countries to condemn North Korea voiced in the United States are absolutely counterproductive and dangerous,” he added, noting they could further escalate tensions.

Last month, Russia attacked a landmark UN resolution condemning North Korea’s human rights record and pledged to ramp up economic ties with the reclusive state.

Russia has invited both Obama and Kim to come to Moscow next year to mark the 70th anniversary of the Soviet Union’s victory over Nazi Germany in World War II.

Russia and the West are locked in a bitter confrontation triggered by Moscow’s annexation of Crimea from Ukraine in March and its support for a separatist uprising in Ukraine’s east.